If you’d like to remove the entire “More Projects” section at the bottom of portfolio project pages, you can add this to your custom CSS or child theme:
.project-navigation {
display: none;
}
Don’t edit the theme files directly, otherwise your changes will be overwritten whenever the theme is updated.
An easy way to add custom CSS is to install the Jetpack plugin and activate the Custom CSS module. You’ll then add your custom CSS in the new stylesheet editor that’ll appear in your dashboard, under Appearance > Edit CSS.
As alternatives, you could either install a standalone custom CSS plugin, or create a child theme.